Method of making fluid self-hardening mixture,preferably for manufacturing foundry moulds and cores



brlUbo nnrnnuwr. LAI'HIIIHLI METHOD OF MAKING FLUID SELF-HARDENING MIXTURE, PREFERABLY FOR MANUFACTUR ING FOUNDRY MOULDS AND CORES Abram Moiseevich Lyass, Sharikopodshipnikovskaya nlitsa 2, kv. 146; Pavel Afanasievich Borsuk, Nizhne-Pervomaiskaya ulitsa 59, kv. 10; Lidia Dorofeevna Snulova Sharikopodshipnikovskaya nlitsa 2, kv. 125; Anna Ivanovna Tsyruleva, Serpovpereulok 3/5, lrv. 8; Elena Vladimirovna Neifak, Nizhne-Pervomaiskaya ulitsa 51/ 10, kv. 9; and Radzhinald Alexeevich Korotkov. Profsojuznaya ulitsa 32/10, kv. 263, all of Moscow, U.S.S.R.

United States Patent F 3,508,936 Patented Apr. 28, 1970 ice making fluid self-hardening mixture, preferably, for producing foundry molds and cores therefrom, composed of a filler, e.g., quartz sand, water glass as a binder, an additive for hardening the mixture which consists of dicalcium silicate or materials comprising dicalcium silicate, a foaming agent selected from the group of anionic and non-ionogenic surface-active agents and water, wherein, according to the invention, abietic resin is also added into the mixture.

The abietic resin is preferably introduced into the mixture in an amount of 0.1 to 0.5 parts by weight. The abietic resin may be introduced into the mixture in the No Drawing. Filed Sept. 27, 1968, Ser. No. 763,388

Int CL 2 7 00; C04 0 form of an alkaline solution (sodium abletate) Of 10- ,s c 10 -3335 2 Claims 15% concentration in an amount of 0.1-1.0 parts by ABSTRACT OF THE DISCLOSURE A method of making a fluid self-hardening mixture, preferably for manufacturing foundry molds and cores,

composed of a filler, for example quartz sand, water lass weight.

The following examples illustrate the invention.

EXAMPLE 1 as a binder, an additive in the form of lcium silicate A fill rQuariz Sand 95.0

or materials containing dicalcium silicate providing for A Wil en-Water glass (aqueous solution of sohardening of the mixture, and a foa 'd dium silicate) of specific gravity 1.48 and from the rou of anionic n n I modulus 2.7 6.0

ac ive agents, said mixture also comprising abietic resin A addi i n for hardening the mixture-dicalin the amount of 0.1-0.5 parts by weig eium silicate 5.0

' A foaming agent from the group of anionic substances-alkyl aryl sulphonate (trademark The abietic resin can be introduced into the mixture in S De ergent Soviet refined alkyl aryl the form of an alkaline solution (sodium abietate) of the s lphonate) 0.1 10-15 concentration in the amount of 0.1-1.0 parts by An additive-Await: resin 0.3 weight. Wat r 1.5-2.0

The present invention relates to foundry, practice, and more particularly to methods of making fluid-self hardening mixtures, preferably for manufacturing foundry cores and molds therefrom.

Known in the prior art is a method of making a fluid self-hardening mixture that consists of a filler, for example, quartz sand, a binder, e.g., water glass, components providing for hardening of the mixture, for example, dicalcium silicate, water and a foaming agent, for example, sulphonic acid (the French Patent No. 1,342,- 529, 1962):

However, although the liquid mixtures thus produced have important technological advantages (free filling of the core boxes with the mixture without compacting it self-hardening of the mixture in the open air, utilization EXAMPLE 2 The mixture is prepared from the following components (in parts by weight):

of inexpensive hardeners), they do not ensure reasonably A filler-Quartz Sand facile knockout of the cores from the castings, especially A P 'iw glass (flqueous 501mm of when the latter have a complex Shape sodium silicate) of specific gravity 1.48 and Furthermore, the proposed mixtures one hour after l l the hardening have a compression strength of 1.5 to 3 ff for hardemng the mlxmrep'Dlcal' kg./cm. and this is often not sufiicient when storing, l S111ate transporting and assembling the cores. When making A foaming agent from the group of amomc complex-shape cores with projections, the latter are often 2 3 aryl l ff (trademark cut down from the cores during the assembly. DS-RAS Detergent Sovlet "fined alkyl aryl It will also be noted that the mixtures prepared by the sulphPPate) known method have a long hardening time (40 to 50 P T P P abmate as an alkahne 50111 minutes), thus considerably increasing the duration of the Q of abletlc of the 10-15% concentra' casting process. This means that these mixtures are unw t 1 5 a er suitable for mass production of molds and cores.

An object of the present invention is to eliminate the above-mentioned disadvantages. Further objects of the invention will become apparent from a consideration of the following description thereof.

The specific object of the invention is to develop a method of making a fluid self-hardening mixture providing for a high compression strength of the mixture in the solid state, a short hardening time and easy knocking of the cores from the castings.

This object is achieved by providing a method of a of the weight of the molding mixture, it changes from the pasty to free-flowing state after a few minutes of mixing.

Thereupon, the liquid mixture can be poured into core boxes and on patterns.

The tests have shown that introduction of abietic resin and sodium abietate into the mixture helps to increase its strength by as much as 2-2.5 times (6-8 kgJcm. when compressing the specimens during 1 hour) as compared with the strength of the fluid mixture without the above additives. Furthermore, the hardening of the mixture is accelerated by 1.5-2 times (10 to 20 minutes), while the knockout of the cores is facilitated by as much as 20 to 30%.

It has been found, that due to material reduction of the brittleness of the hardened mixture, the break-down of the cores and projecting portions is reduced by as much as 50 percent.

The hardened cores and molds do not require thermal drying and can be filled with molten metal just after their manufacture.

The cores and molds made of the above described mixtures can be employed for manufacturing castings of steel, iron and non-ferrous metal alloys.

It has also been found that when casting non-ferrous alloys addition of abietic resin or sodium abietate into the mixture helps to produce castings with a smooth surface.

In other instances of employing the above method, an aqueous solution of potassium silicate can be used as a binder.

Although the present invention is described in connection with the preferred exemplary embodiments, it will be understood that changes and modifications may be made without departing from the scope of the present invention, as will be readily understood by those skilled in the art.

What is claimed is:

1. In a method of making a fluid self-hardening mixture, for manufacturing foundry molds and cores wherein there are mixed dry components of sand, and dicalcium silicate whereafter there is added to the dry components, a liquid comprising water glass, an anionic foaming agent and water, the liquid and dry components being mixed to form a free-flowing mixture, an improvement comprising adding abietic resin to the mixture of dry components in an amount between 0.1 and 0.5 parts by weight of said mixture.

2. A method as claimed in claim 1 wherein said abietic resin is an alkaline solution of sodium abietate of 10-15% concentration.

References Cited UNITED STATES PATENTS 1,910,799 5/1933 Kennedy 106--38.6 1,978,948 10/1934 Kennedy et a1 l0638.6 3,424,600 1/1969 Liass et al. 106-383 JULIUS FROME, Primary Examiner.

L. B. HAYES, Assistant Examiner US. Cl. X.R. 

